Method and device for embedding and detecting watermark information

Abstract

The invention relates to a method and a device for embedding and detecting watermark information. The invention provides the method for embedding the watermark information into a text image, comprising the following steps: an error correction of coding step: carrying out error correction of coding on the watermark information to be embedded into a text image, and generating a watermark information bit stream; a unit division step: dividing the text image into unit images by taking a character or a character string as a unit; a stroke end point determination step: determining all stroke end points in the unit images; a stroke end point sequence generation step: arranging the stroke end points in a unique stroke end point sequence irrelevant to the inclination of the text image; and a stroke end point changing step: embedding the watermark information bit stream into the stroke end point sequence, and determining whether to change the stroke end points and / or the adopted change mode according to the embedded watermark information bits. The invention also provides a method for detecting the watermark information embedded into the text image, which is used for detecting the embedded watermark information.

Description

technical field [0001] The present invention relates to a method and equipment for embedding watermark information into text images and a method and equipment for detecting embedded watermark information from text images. The present invention generally relates to the embedding and detection technology of text digital watermark information in printed documents in the technical field of text digital watermark, and can be applied to the technical fields of information engineering and document protection. Background technique [0002] Digital watermarking technology is an important part of the field of information hiding technology. It uses digital processing methods to hide information of specific significance in digital products such as images, audio and video, and text in a way that is not easy to perceive, and detects all information through certain technical means. hidden information. This technology can be used for copyright protection of digital products, content verifi...

AI Technical Summary

Problems solved by technology

[0006] Chinese Patent Application Publication No. CN 101119429 A provides another method for embedding a watermark, in which the character outline is reversed according to a certain step size of the odd or even number to embed the watermark. The step size is the same as the threshold value in the US6983056 B1 patent. The form of experience value exists, in fact, they are affected by the depth and binarization of printing and scanning, and it is difficult to achieve a balance between vision and anti-printing and scanning ability through technical means

Designing different topological structures for different characters and different fonts requires a considerable amount of work. At the same time, in its technical implementation, it is necessary to first complete the recognition of semantic characters, that is, OCR (Optical Character Recognition) processing, and then query the "table" To realize the embedding and detection of the watermark, which undoubtedly increases the difficulty and complexity of the implementation

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